U.S. patent application number 09/765593 was filed with the patent office on 2002-10-10 for method and system for providing instant start multimedia content.
This patent application is currently assigned to SONY COMPUTER ENTERTAINMENT AMERICA. Invention is credited to Corson, Greg.
Application Number | 20020147979 09/765593 |
Document ID | / |
Family ID | 25073948 |
Filed Date | 2002-10-10 |
United States Patent
Application |
20020147979 |
Kind Code |
A1 |
Corson, Greg |
October 10, 2002 |
Method and system for providing instant start multimedia
content
Abstract
A system and method for providing multimedia content through a
cable, satellite television or other content server system. A
server facility which provides multimedia content divides formatted
multimedia content into data chunks (e.g., collections of data
corresponding to one minute lengths) prior to transmission to a
user/subscriber receptor unit, and sends the divided data chunks
according to a schedule which permits instantaneous starting and
viewing of the multimedia content, such as movies, upon
user/subscriber request. The user/subscriber receptor unit includes
a cable box, video game device, or the like having a digital video
recording capability and at least a memory capacity or disk space
sufficient to store a complete unit of media content, such as
full-length feature film. The invention does not require intensive
interaction between the server facility and the receptor unit, but
rather, only requires sending of content signals in the form of an
interleaved media stream from the server facility to the receptor
unit. Further, the invention requires the use of no more than six
times the bandwidth of the original signal for operation.
Inventors: |
Corson, Greg; (Foster City,
CA) |
Correspondence
Address: |
PAUL A. GUSS
PAUL A. GUSS ATTORNEY AT LAW
775 S 23RD ST FIRST FLOOR SUITE 2
ARLINGTON
VA
22202
|
Assignee: |
SONY COMPUTER ENTERTAINMENT
AMERICA
919 EAST HILLSDALE BLVD. 2ND FLOOR
FOSTER CITY
CA
94404
|
Family ID: |
25073948 |
Appl. No.: |
09/765593 |
Filed: |
January 22, 2001 |
Current U.S.
Class: |
725/90 ;
348/E7.069; 725/87 |
Current CPC
Class: |
H04N 21/47208 20130101;
H04N 21/26241 20130101; H04N 21/26216 20130101; H04N 21/8456
20130101; H04N 21/4331 20130101; H04N 21/26266 20130101; H04N
21/262 20130101; H04N 21/26208 20130101; H04N 21/26275 20130101;
H04N 7/173 20130101 |
Class at
Publication: |
725/90 ;
725/87 |
International
Class: |
H04N 007/173 |
Claims
What is claimed is:
1. A method for delivering digital content from a server facility
to a user/subscriber, comprising: providing, in said server
facility, formatted digital content which has been divided into a
plurality of data chunks prior to transmission; providing a
communications network for transmitting said digital content;
providing a user/subscriber control device for receiving, storing
and playing the transmitted digital content; and transmitting the
divided data chunks from said server facility according to a
predetermined time schedule.
2. The method according to claim 1, further comprising dividing
said digital content into said plurality of data chunks in the
server facility.
3. The method according to claim 1, wherein said formatted content
comprises n data chunks, each data chunk occupying a substantially
equal unit of time, and wherein said transmitting step comprises
transmitting an nth data chunk once every n units of time.
4. The method according to claim 1, further comprising selecting
digital content provided by the server facility.
5. The method according to claim 1, further comprising scheduling
the transmission of at least one of said data chunks for
non-sequential transmission.
6. The method according to claim 1, further comprising transmitting
at least one data chunk non-sequentially.
7. The method according to claim 1, further comprising storing at
least one data chunk non-sequentially onto the control device.
8. The method according to claim 1, wherein the transmitted data
chunks are made available for immediate consumption by a
user/subscriber.
9. The method according to claim 1, wherein at least one
transmitted data chunk is stored on the control device prior to
consumption by a user/subscriber.
10. The method according to claim 1, wherein at least one data
chunk is stored onto the control device prior to selection by a
user/subscriber.
11. The method according to claim 1, wherein a data chunk is
consumed while at least one data chunk is simultaneously stored
onto the control device for subsequent consumption.
12. A method according to claim 1, wherein said control device has
a data memory for storing at least one complete version of said
digital content.
13. The method according to claim 1, wherein said digital content
comprises at least one of video, audio and graphics.
14. The method according to claim 1, further comprising using less
than the maximum number of channels of available digital signal
bandwidth per transmission signal.
15. The method according to claim 1, further comprising dedicating
at least one transmission signal to common portions of digital
content.
16. The method according to claim 15, wherein said common portions
include at least one of ratings notices, copyright notices, sound
production logos and production trademarks and service marks.
17. The method according to claim 1, further comprising providing a
number n of digital content starts per digital transmission signal,
wherein 1<n<M and M is the maximum number of channels of
bandwidth per signal.
18. The method according to claim 1, further comprising: allocating
one multi-channel digital signal to an initial user/subscriber
according to a transmission schedule of divided data chunks; adding
subsequent users/subscribers to said transmission schedule for said
one signal; and receiving said data chunks by said subsequent
users/subscribers simultaneously with those being transmitted to
the initial user/subscriber following a request for said digital
content.
19. The method according to claim 1, further comprising using a
same amount of maximum signal bandwidth for digital content
irrespective of how many users/subscribers have requested and are
receiving such content transmitted to their control device.
20. The method according to claim 1, wherein said control device
includes a digital cable/satellite set-top-box and/or video game
console unit.
21. The method according to claim 1, wherein said control device
includes at least one of an external memory storage device, an
internal memory storage device and a detachable storage medium.
22. The method according to claim 1, further comprising modifying
digital content consumption variables, wherein said variables
include, speed, direction of play and volume of the digital
content.
23. A system for delivering digital content from a server facility
to a user/subscriber, comprising: a digital content database; a
server facility which provides formatted digital content which has
been divided into discrete data chunks prior to transmission; a
user/subscriber control device for receiving, storing and playing
said transmitted digital content; and a communications network for
transmitting said divided data chunks from said server facility
according to a predetermined time schedule.
24. The system according to claim 23, wherein said server facility
comprises means for dividing said digital content into said divided
data chunks.
25. The system according to claim 23, wherein said server facility
divides said formatted content into n discrete data chunks, each
data chunk occupying a substantially equal unit of time, and
wherein an nth data chunk is transmitted from said server facility
once every n units of time.
26. The system according to claim 23, wherein at least some of said
data chunks are transmitted and stored non-sequentially on said
control device prior to user/subscriber consumption of the digital
content.
27. The system according to claim 23, wherein said data chunks are
transmitted and stored prior to selection of the digital
content.
28. The system according to claim 23, wherein said data chunks are
transmitted and stored prior to user/subscriber consumption of the
digital content.
29. The system according to claim 23, wherein said control device
includes a digital cable/satellite set-top-box and/or video game
console unit.
30. The system according to claim 23, wherein said control device
includes at least one of an external memory storage device, an
internal memory storage device and a detachable storage medium.
31. The system according to claim 23, wherein said server schedules
the transmission of at least one of said data chunks for
non-sequential transmission.
32. The system according to claim 23, wherein said server transmits
at least one data chunk non-sequentially.
33. The system according to claim 23, wherein said control device
permits the storing of at least one data chunk
non-sequentially.
34. The system according to claim 23, wherein said control device
makes the transmitted data chunks available for immediate
consumption by a user/subscriber.
35. The system according to claim 23, wherein said control device
has a data memory for storing at least one complete version of said
digital content.
36. The system according to claim 23, wherein said server facility
uses less than the maximum number of channels of digital signal
bandwidth for a transmission signal.
37. The system according to claim 23, wherein said server facility
dedicates at least one transmission signal to common portions of
digital content.
38. The system according to claim 23, wherein said server facility
provides a number n of digital content starts per digital
transmission signal, wherein 1<n.ltoreq.M and M is the maximum
number of channels of bandwidth per signal.
39. The system according to claim 23, wherein said server facility
allocates one multi-channel digital signal to an initial
user/subscriber according to a transmission schedule of said
divided data chunks; adds subsequent users/subscribers to said
transmission schedule for said one signal; and permits the
receiving of said data chunks by said subsequent users/subscribers
simultaneously with those being transmitted to the initial
user/subscriber following a request for said digital content.
40. The system according to claim 23, wherein said server uses a
same amount of maximum signal bandwidth for digital content
irrespective of how many users/subscribers have requested and are
receiving such content transmitted to their control device.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] This invention generally relates to the field of digital
computer systems and particularly in the field of video and
multimedia computer servers and systems, along with the associated
delivery of such content to a user/subscriber premises.
[0003] 2. Description of the Related Art
[0004] Distribution of full motion video and audio data has evolved
from early television broadcasting to meet viewer demand. Earliest
video distribution was by point-to-point wiring between a camera
and a video monitor. This was followed by scheduled television
broadcasting of programming over the public air waves. In the
1960s, Community Antenna Television (CATV) was chartered to provide
off-air television signals to viewers in broadcast reception fringe
areas. Later, under FCC regulation, the CATV industry was required
to provide local access and original programming in addition to
off-air broadcast signal distribution.
[0005] In response, several sources of cable network programming
were established. Because of the wide bandwidth available on cable
television systems, additional channels were made available for the
new programming. However, programming was generally prescheduled,
with the viewer left to tune to the designated channel at the
appointed time to view a particular program.
[0006] To increase revenues, cable television systems have
initiated distribution of premium channels viewable only by
users/subscribers having appropriate descramblers. The descramblers
are tuned to receive only premium channels, descramble the video
and audio information and supply a signal capable of reception on a
standard television set.
[0007] Pay-per-view programs, which evolved later, include recently
released movies, live concerts, popular sporting events, etc.
Users/subscribers wishing to view a pay-per-view program place an
order with the cable operator. At the designated time, the
user/subscriber's descrambler is activated to permit viewing of the
pay-per-view programming. However, the user/subscriber is
restricted to viewing the programming at the scheduled time. There
is no capability of delivering programming to a user/subscriber on
demand, that is, immediately or at a user/subscriber-specified time
and date.
[0008] In the early 1980s, technological advances resulted in the
proliferation of Video Cassette Recorders (VCR), establishing a
second course for video programming distribution. Pre-recorded
video programs are now available for sale and rental to VCR owners.
Using a VCR, the viewer selects from among many titles available
for sale and rental, and views the program when convenient. The VCR
owner further has the capability to selectively view the
programming using special functions of the VCR, such as pause, fast
forward, reverse, slow motion, etc. The viewer can thus manipulate
and replay portions of the program at will.
[0009] The penalty for this convenience, however, is in the
necessity to travel to the local video rental/sales store, if
necessary wait for a popular video program tape to become
available, once the program is obtained return home to view it and
then revisit the video store to return the tape.
[0010] Telephone lines have been suggested as an alternative means
of video distribution in Goodman et al., U.S. Pat. No. 5,010,399
and Kleinerman, U.S. Pat. No. 4,849,811. However, systems using the
public switched telephone network (PSTN) are often bandwidth
limited, providing only still frame or video conferencing
capabilities. Because telephone system carriers for the most part
use the PSTN only for connectivity between users/subscribers, there
is no capability for dynamic routing of digitized video without
dedicated leased, wide bandwidth circuits. Telephone line-based
systems also fail to provide acceptable VCR type functional control
of the programming.
[0011] Alternatively, the Internet, World Wide Web, cable and
satellite delivery systems continue to provide growing bandwidth
communication channels which will soon interconnect most households
and businesses and promise to provide many services to connected
users. These services include instant access to large databases of
financial, educational and other multimedia information, in
addition to real-time interaction with virtual communities of
people with similar interests. Among the services that will be
available, one that has received a great deal of corporate and
media attention is the provision of video on demand (VOD).
[0012] VOD holds out the promise that almost every movie ever made
will be available to a user of the service at any time. Instead of
driving to a video rental store and selecting a movie, users will
be able to select any movie stored in the multimedia content server
system's video library and have that movie delivered to them over
the Internet, or by cable or satellite systems.
[0013] Before the promise of VOD can be realized, many problems
must be solved. Even a relatively short film of two hours duration
contains approximately 2.2.times.10.sup.10 bits of data. Standard
methods to compress and store the vast quantity of data contained
in a film library of thousands of titles must be agreed upon. Even
after the data has been captured and stored, there is no industry
agreement as to what system will be needed to deliver the stored
data to users.
[0014] Any proposed system must satisfy rigorous user demands.
Users will want whatever film they have selected delivered to them
quickly. They will also want the ability to start and stop the film
at any point, as well as the ability to fast forward (FF) and fast
reverse (FR) the film at will. According to existing prior art
systems, this typically done by sending a unique stream of data
(i.e., the movie) to each subscriber. However, because thousands of
people could be watching the movie at the same time, providing
these capabilities to every user at any time would place enormous
demands on the system's storage units, internal buses, and
processing units. Even the enormous bandwidth of fiber optic cable
may be exceeded.
[0015] Additionally, some two-way communication between the user
and the system is necessary to communicate users' requests, as well
as billing information and the like. This two-way communication
places additional burdens on the system.
[0016] Programming-on-demand cable systems have been proposed which
allow any one of a plurality of individual users to request any one
of a plurality of video programs they wish to view (time delayed)
from the server's library of programs, and permits the requested
program to be available for subsequent viewing on a conventional
television set at the user's location following a request initiated
by the user/subscriber. Each program is pre-stored in a digital
storage device and is selectable by a host computer or server
system at the headend facility in response to an address signal
transmitted from the user/subscriber. The host computer in
conjunction with other communication and data processing hardware
and software transmits the video program as digital data at a high
non-real-time rate over a high bandwidth system, such as a fiber
optic line network, to a data receiving station at the
user/subscriber's premises, e.g., set-top-box (STB). The STB then
stores the digital content for subsequent real-time transmission to
the user's television set. Such systems permit the user/subscriber
to view any one of a number of programs transmitted on a
non-real-time basis, and also allows the user to store the
transmitted program on the STB for an indefinite period of time for
viewing at a later date.
[0017] Various methods have been proposed for transmitting the
programs on a non-real-time basis. For example, referring to FIG.
1, a typical video server (VS), as disclosed by Verhille et al. in
U.S. Pat. No. 5,539,448, is used in a video on demand network
wherein video signals are transferred over a communication network
(TSY) from the video server to respective terminals connected to
the network. The system includes digital storage facilities (DSF),
a server control means (SCM), a broadband switch (BS) having first
ports (VP1/VPY) to which the storage facilities (DSF) are coupled,
second ports (CL) coupled to the communication network (TSY) and a
third port (CP) to which the server control means (SCM) is coupled.
The server control means (SCM) controls the transfer of digital
video content from the storage facilities (DSF) and through the
switch (BS) and the communication network (TSY) to the terminals.
The broadband switch (BS) also has a set of fourth ports (CP1/CPX)
to which system adapters (SYA1/SYAX) are coupled to adapt the video
signals to a format which is compatible with the communication
network. The server control means (SCM) performs the transfer of
video signals firstly from the digital storage facilities (DSF) to
the system adapters (SYA1/SYAX) through the switch (BS) and then
from the adapter means to the terminals via the communication
network (TSY). The system adapters include channel memories and
adapters to perform rate and format adaptation of the video signals
respectively. The channel memories and the adapters can be directly
and separately coupled to the broadband switch.
[0018] In operation, video servers like that of Verhille et al.
receive user requests transmitted from multiple users' STBs through
a distribution network to the server. The requests are routed on to
a real time controller, which furthers them to a system controller.
If the system controller determines that a given user is permitted
access and that the requested video data is in the storage system,
the system controller orders the real time controller to permit
user access and tells the real time controller where the video data
is stored.
[0019] The server facility transmits coded digital video data over
a broadband PSTN which supplies connectivity to the facility. A
user/subscriber may use either a standard telephone instrument over
the PSTN or a dedicated control device over an ISDN packet network
to order the video programming. Such a device is located at the
television set of the user/subscriber and permits a display of the
program menu on the television screen.
[0020] Connectivity between the server facility and the
user/subscriber for transmission of video data is provided by an
asymmetrical digital user/subscriber line (ADSL) system. ADSL
interface units perform multiplexing of digital video information
with voice information to be transmitted to the user/subscriber and
support transmission on the ISDN packet data network of a reverse
control channel from the user/subscriber to the server
facility.
[0021] However, conventional video on demand services do not
include an integral and comprehensive library of video program
material that can be stored directly on the user/subscriber's STB,
and hence enable only limited storage capabilities for video and
audio data supplied by the server. Enhanced scheduling
functionality is required to efficiently support multiple
users/subscribers over a temporally diverse programming range.
Furthermore, to support network management and enable instantaneous
access to multimedia content, a need remains for a system which
does not require dynamic interaction with network facilities or to
reconfigure network resources in real-time in response to
multimedia content requests by plural users/subscribers.
SUMMARY OF THE INVENTION
[0022] A general object of the present invention is to provide a
system and method for delivering multimedia content, such as video
and audio, by means of cable, satellite television or other systems
that permit immediate viewing of the content upon user/subscriber
request, along with the use of a user/subscriber receptor unit
having digital video recording capabilities having at least the
memory capacity to store a complete unit of media content, such as
full-length feature film.
[0023] Another object of the invention is to provide a system and
method that does not require the continuous or even periodic
interaction between the server facility and the user/subscriber
receptor unit, and in particular where the system can function over
a one-way network in which all users are being sent the same
signal.
[0024] A further object of the present invention is to divide the
multimedia content into data chunks which are transmitted and
recorded on the user/subscriber's STB "just in time" prior to
needing to be viewed.
[0025] A further object of the invention is to provide a system and
method that requires the use of no more than 6 times the bandwith
of the original signal for enabling instantaneous start of video
content for an unlimited number of users. In addition, the
bandwidth requirement is non-constant, wherein the peak bandwidth
is only periodically needed to provide VOD capability.
[0026] Another object of the invention is to provide for the
enhanced efficient use of available bandwidth by reducing the
bandwidth required while still providing immediate viewing, which
may be accomplished by pre-storing portions of the multimedia
content on the user/subscriber's STB.
[0027] Yet another object of the invention is to provide a system
and method of dedicating at least one signal from the server
facility to common portions of multimedia content, e.g., film
starts only, thus avoiding the need for the associated memory space
usage on the user/subscriber's STB.
[0028] Another object of the invention is to provide for a number
of multimedia content starts of up to the maximum number of
channels of signal bandwidth.
[0029] Another object of the invention is to provide a system and
method of allocating one multi-channel signal to an initial
user/subscriber followed by adding subsequent users/subscribers to
a transmission schedule in such a manner that the subsequent
users/subscribers will receive the multimedia data chunks
simultaneously with those transmitted to the initial
user/subscriber.
[0030] A further object of the invention is to prevent any single
multimedia content product, e.g., a film, from requiring more than
the maximum bandwidth per signal irrespective of how many
users/subscribers have requested the content and are having such
content transmitted to their STBs.
[0031] Another object of the invention is to reduce the cost of
adding new users/subscribers to multimedia content already in the
progress of being transmitted, as opposed to systems and methods
where a separate and unique stream of multimedia content is
transmitted to each user/subscriber.
[0032] A further object is to allow new users to be added to an
existing multimedia stream at a less-than-incremental cost in
bandwidth.
[0033] The above and other objects, features and advantages of the
present invention will become more apparent from the following
description when taken in conjunction with the accompanying
drawings in which preferred embodiments of the present invention
are shown by way of illustrative example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 shows a prior art video on demand (VOD) system.
[0035] FIG. 2 illustrates an overall system configuration enabling
the immediate VOD capability according to an embodiment of the
present invention.
[0036] FIG. 3 illustrates packaging of discrete data portions of a
digital multimedia content signal according to an embodiment of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] The present invention is a system and method for providing
multimedia content, such as video and audio, by means of cable,
satellite television or other content providing systems. The
invention permits the instantaneous consumption, e.g., viewing, of
content, such as movies upon user/subscriber request. The system
employs a user/subscriber receptor unit (set-top-box or STB)
comprising a programmable video reception and playback device
having a digital video recording capability, similar to TIVO.TM. or
other known units having at least the memory (e.g., disk space) to
store a complete unit of media content, such as full-length feature
film.
[0038] The invention does not require intensive interaction with
the STB, but simply requires continuous one-way sending and receipt
of content signals from the media content server to the receptor
unit. The receptor unit can be tuned into the server and enable
viewing of the content at anytime. Further, in the worst case, the
invention requires the use of no more than 6 times the bandwidth of
the original signal.
[0039] In the present disclosure, the term "instantaneous" shall be
understood to mean substantially instantaneous as in on the order
of one minute or so.
[0040] The invention can be applied to any form of digital
streaming content such as, but not limited to, films, TV programs,
motion control data and music. For the purpose of simplifying the
description of the invention, examples such as, the streaming films
on a pay-per-view TV system will be used. Because of the way
pay-per-view systems are currently implemented, use of the
invention in such an environment would have considerable
benefits.
[0041] FIG. 2 shows the configuration of a system for enabling a
video on demand capability according to an embodiment of the
present invention. The term "multimedia content" in the context of
the specification and claims shall be understood to refer to a
collection of downloadable contents which may consist of any one of
video linear streaming data, such as motion pictures in the MPEG-2
format, linear audio streaming data such as MP3 data, binary
program data, high-resolution graphics data or any combination of
such data. The server facility 10 is a server system which manages
user/subscriber requests for multimedia content. Access to the
sever 10, which may comprise one of several servers, is facilitated
through a typical device known as a router (not shown) on the LAN
30, which directs requests to the multimedia server 10. In this
embodiment, the multimedia content database 20 is coupled to the
server. When the server 10 receives requests from a
user/subscriber, the server 10 executes the transmission of media
content from the database 20.
[0042] The network 40 is normally a bi-directional digital
communications network that connects the users/subscriber's control
device 50 with the multimedia server 10. With current technologies,
a CATV bi-directional network, ISDN or XDSL high speed networks and
satellite networks are examples of existing infrastructures
enabling the necessary network connections for implementing the
present invention.
[0043] The user/subscriber's side of the system configuration
comprises a control device, e.g., a set-top-box, which may be video
game console, for example, including a detachable storage medium 60
therein or external thereto, and a visual monitor or any other
suitable display device 70 connected to the control device 50. In a
preferred embodiment, the detachable storage media 60 comprises a
CD-ROM or DVD disc.
[0044] The networked control device 50 is preferably a network
connectable player of digital multimedia content having a video
recording function, including a hard drive (not shown) therein
having sufficient recording capacity for recording at least a
full-length motion picture. Such a device 50, according to
conventional methods, normally utilizes the detachable storage
media 60 as a contents distribution media in a non-networked
environment. Stated otherwise, under ordinary use according to
conventional known methods, the control device 50 is capable of
playing back media contained on the detachable storage media 60,
which is commonly an interactive video game, for example, even if
the device is not connected to the network. The control device 50
may also be used for viewing of DVD video content provided on the
detachable storage media 60, and according to the present
invention, also enables recording, on the hard drive, of video
content downloaded from the server facility and transmitted through
the network 40.
[0045] Although FIG. 2 illustrates a video-on-demand system
operating over a bi-directional network, it should be understood
that the principles of the invention are fully applicable to a
one-way network, wherein all users are sent the same signal from
the server facility simultaneously, and wherein upstream data
transmissions from the usre/subscriber's side are not
necessary.
[0046] Digital cable TV and satellite systems broadcast many
signals each containing digital data at 25-30 megabits per second
(mbps) of data, wherein 100 signals is common in a typical cable TV
system. STBs generally contain one or more tuners for receiving
these digital broadcast signals. The digital data on each signal
generally contains multimedia content in one of a number of
industry standards, such as MPEG-2 compressed video for several
channels, typically five or six in number. A user/subscriber STB
containing a digital multimedia recording capability, and having a
plurality of digital signal tuners, can record one channel while
the user/subscriber views another. The standard STB, having two
tuners, is presently capable of tuning in up to 60 mbps of digital
data at once.
[0047] With reference to Table 1, a conventional satellite, cable
or other multimedia service provider will typically dedicate six
channels, which is one 30 mbps digital signal, and permits
transmission of a two and one-half hour movie for example. These
six channels allow for the sending of six complete copies of the
movie each starting at 30 minute intervals. Table 1 illustrates
such a viewing schedule. Each occurrence of the narrative movie
title represents one specified showing of the two and one-half hour
movie. All six channels are transmitted on a single digital signal
and are subsequently received by the user/subscriber's STB.
1TABLE 1 (Conventional System) 1
[0048] Accordingly, when the user/subscriber begins viewing the
film at 7:00 p.m., for example, as the STB is showing the first
half-hour between 7:00 p.m. and 7:30 p.m. on channel 504, the STB
simultaneously receives (although the viewer does not ordinary
view) the second half-hour on channel 503, the third on 502, the
fourth on 501, the fifth on 500 and the sixth on 505. Thus, for a
STB having a digital recording capability, the entire movie could,
in actuality, be recorded in one half-hour, although in the
conventional case the user simply views the entire movie on one
channel unaware of what is being simultaneously sent on the other
channels.
[0049] Hence, in the case of existing conventional pay-per-view TV
systems, the same movie is frequently transmitted at staggered
start times, such as every half hour as shown in Table 1, over
multiple TV channels. This can require people to wait up to as long
as one half hour to begin viewing a movie. By contrast, with the
present invention, as shall be described below, the waiting time
can be reduced to less than one minute, allowing for true "video on
demand."
[0050] To provide an improvement over the conventional system, the
present invention offers a system and method whereby any form of
digital streamed content can be converted into a new type of stream
of one-way data (hereinafter referred to as an Interleaved
Multimedia Stream or IMS) in which a plurality of receivers can
begin receiving the IMS at different times during transmission
thereof, while still allowing each receiver to present the content
in a proper time sequence from beginning to end. To create an IMS,
the original signal content stream is broken into smaller "chunks"
of data (such as 1 minute in length), wherein each data chunk is
repeatedly transmitted on a regular schedule which guarantees that
regardless of when a particular receiver begins reception of the
stream, each necessary chunk of data will be received "just in
time" for playback.
[0051] For successful operation, the system requires that the
receiver or STB be equipped with a local digital storage means so
that the STB can receive the chunks of content in any order and at
any time, store them immediately and then present the data chunks
for viewing in their proper order, speed and time.
[0052] More specifically, as illustrated in FIG. 3, the present
invention divides the digital information into smaller discrete
units or "chunks" corresponding to one minute (or any other
suitable and convenient unit time) of video content each, and sends
them in such a manner that they arrive at the STB just in time to
be recorded onto its hard disk drive before they are needed for
playback. FIG. 3 shows that when a 30 mbps system having each one
minute unit of video being 5 mb long is used, five additional
minutes, i.e., bandwidth slots 2-6, of video can be sent to the STB
simultaneously for every one minute of video that is being
viewed.
[0053] Accordingly, the invention provides a system and method for
delivering instantaneous multimedia content from a server facility
to a user/subscriber. The server facility, as illustrated in FIG.
3, includes a function for dividing formatted content into discrete
data chunks prior to their transmission. The communications network
facilitates the transmission of the selected content as an
interleaved multimedia stream composed of such data chunks. The
user/subscriber control device receives and stores the data chunks,
and then organizes the chunks and plays the content back in its
proper order, speed and time.
[0054] To convert a normal digital video stream into the [MS format
of the present invention, the original digital video stream is
divided into data chunks, such as one minute segments or any other
convenient unit of time. Each of these chunks must be transmitted
with a frequency equal to its time index in the video. Thus, to
permit a movie to begin on one minute's notice, the first minute of
video content needs to be transmitted repeatedly once per minute,
with the second minute being sent every two minutes, the third
every three minutes, the tenth every ten minutes and so forth. That
is, in the case of n discrete data chunks, each data chunk
occupying a substantially equal unit of time, an nth data chunk is
sent once every n units of time. As long as this scheduling rule is
followed, regardless of when a subscriber tunes into the data
broadcast, every data chunk is guaranteed to arrive at their STB
sometime before it would normally be viewed. A chunk may be sent
earlier than necessary so long as the rule of sending every nth
chunk on or before the nth minute is always obeyed.
[0055] As a more specific example, Table 2 illustrates a typical
transmission schedule of the present invention for a ten minute
video. Each horizontal row represents one minute of time, each
column represents one sixth of one minute, which is the time-frame
necessary to transmit one minute of video. The numbers in each box
depict which precise portion, e.g., minute, of video is being sent
in the specified slot.
2 TABLE 2 Time 1 1 2 1 2 3 1 3 4 1 2 4 5 1 5 6 1 2 3 6 7 1 7 8 1 2
4 8 9 1 3 9 10 1 2 5 10 11 1 12 1 2 3 4 6 13 1 14 1 2 7 15 1 3 5 16
1 2 4 8 17 1 18 1 2 3 6 9 19 1 20 1 2 4 5 10 21 1 3 7 22 1 2 23 1
24 1 2 3 4 6 8 25 1 4 5 26 1 2 27 1 3 9 28 1 2 4 7 29 1 30 1 2 3 5
6 10 31 1 32 1 2 4 8
[0056] As seen in Table 2, unit 1 is transmitted at minute 1, while
in minute 2 unit 1 and unit 2 are transmitted and both can be
viewed. After unit 2 is viewed, unit 3 is transmitted and viewed.
In minute 4, units 1, 2 are simultaneously transmitted in the two
slots preceding the third slot, which itself contains unit 4 for
viewing. In minute units 1 and 5 are transmitted. In minute 6,
units 1, 2 and 3 are transmitted in the three slots prior to unit
6. Thus, the invention's scheduling permits an interleaving of the
transmitted data chunks for storage on the STB which may or may not
be needed for immediate viewing by the user/subscriber.
[0057] In any event, between the unit being viewed and the units
being simultaneously stored on the STB, the user/subscriber is able
to view the movie as a seamless multimedia stream, even though the
data chunks do not have to be sent serially. For example, if a new
user/subscriber begins viewing unit 1 in minute 24, units 2, 3, 4,
6 and 8 are simultaneously stored during this same initial minute.
Thus, three additional minutes pass before unit 5 is needed.
However, in minute 25, unit 5 is transmitted and recorded on the
STB unit, while unit 6 has been previously transmitted and recorded
during the previous minute 24 as indicated above. Unit 7 is
transmitted in minute 28, which is only 4 minutes after the start
of viewing by the user/subscriber at minute 24, so unit 7 has been
transmitted prior to its need to be viewed. Unit 8 has also been
previously stored in minute 24. Further, unit 9 was transmitted in
minute 27, while unit 10 is transmitted in minute 30. Therefore,
the entire 10 minute movie has been transmitted within six minutes
after the completion of the initial viewing of unit 1 by the
user/subscriber at minute 24.
[0058] The present invention's system and method permits the
required peak bandwidth not to exceed that illustrated in Table 2,
so that no more than six times the bandwidth of the original signal
is needed. This is a result of the fact that as the movie is
progressively viewed later segments of the movie are sent less
frequently.
[0059] As seen in Table 2, the number of discrete bandwidth units
for each specified divisible unit of time, e.g., one minute, is not
constant. For example, only one sixth of the available bandwidth is
utilized in line 23 (minute 23), while in line 24 all of it is
used. Thus, the present invention permits each unit of data to be
delivered to the STB just in time, or even earlier than necessary,
for viewing as a means of "data averaging" the sent units over time
when additional bandwidth is available, such as at line 15 (minute
15).
[0060] Table 3 illustrates relative discrete data chunks being
presently viewed and corded, along with those previously recorded
when the user/subscriber initiates play minute 15 (line 15) based
upon the schedule of Table 2.
3TABLE 3 Time Index Currently Playing Currently Recording On Disk
15 1 1, 3, 5 16 2 2, 4, 8 1, 3, 5 17 3 1, 2, 3, 4, 5, 8 18 4 6, 9
1, 2, 3, 4, 5, 8 19 5 1, 2, 3, 4, 5, 6, 8, 9 20 6 10 1, 2, 3, 4, 5,
6, 8, 9 21 7 7 1, 2, 3, 4, 5, 6, 8, 9, 10 22 8 1, 2, 3, 4, 5, 6, 7,
8, 9, 10 23 9 24 10
[0061] Similarly, Table 4 illustrates the initiation of play on
minute 11 (line 11). It should also be noted that the invention
permits the user/subscriber to vary the speed and direction of the
presently viewed movie. So long as the recording process continues,
the user/subscriber can pause or rewind/review the movie at any
time. Assuming the next content portion (data chunk) is already
available on the disk, the user/subscriber can also fast
forward.
4TABLE 4 Time Index Currently Playing Currently Recording On Disk
11 1 1 12 2 2, 3, 4, 6 1 13 3 1, 2, 3, 4, 6 14 4 7 1, 2, 3, 4, 6 15
5 5 1, 2, 3, 4, 6, 7 16 6 8 1, 2, 3, 4, 5, 6, 7 17 7 1, 2, 3, 4, 5,
6, 7, 8 18 8 9 1, 2, 3, 4, 5, 6, 7, 8 19 9 1, 2, 3, 4, 5, 6, 7, 8,
9 20 10 10 1, 2, 3, 4, 5, 6, 7, 8, 9
[0062] The basic structure and operation of the present invention
has been described above. Next, other variants and improvements on
the basic system shall be described as additional embodiments of
the invention.
[0063] In one such embodiment, the present invention permits the
pre-storing of data chunks making up the early portions of a movie
onto the STB. Moreover, the invention permits the non-sequential
transmission and storage of data chunks onto the user/subscriber
control device. Accordingly, since the initial portions or minutes
of the film are transmitted most often, the invention allows the
required bandwidth to be reduced by having those portions
pre-stored. The pre-storing of data is performed on a temporally
low-priority basis, such as at night time or whenever the
user/subscriber regularly is not viewing content. Further, portions
such as the first few minutes of films, both presently and in the
future by design, often contain common subject matter. These
portions presently contain such features as a ratings pages,
copyright notices, sound production logos such as Dolby.RTM., as
well as studio logos like Sony Pictures.RTM., etc. The invention
permits these features to be pre-stored on the hard drive of the
STB, thus saving bandwidth. Furthermore, the first portions of a
film are commonly at a lower bit rate, as they may be just static
images, such as titles, which also reduces bandwidth.
[0064] In yet another embodiment, as an alternative to storing film
starts on the hard drive of the STB as described in the preceding
paragraph, as illustrated in Table 5, at least one signal (composed
of six times the bandwidth of the original signal), which is
automatically received by the STB whenever a movie is requested,
may be dedicated to carrying "film starts" only. This permits more
free memory, e.g., disk space, in the STB to be utilized for other
non-pre-storing functions. Multimedia content start requests
initiated by users/subscribers and generated by plural respective
STBs are collected by the server until there is an open slot on the
"film start" channel, that is, until the film start for the
requested movie comes around again on a given channel within the
signal, whereupon the film start is sent to the STB and movie
viewing and recording in accordance with the procedures described
for Table 1 may begin.
5 TABLE 5 TIME Channel 05:00 05:01 05:02 05:03 05:04 . . . 500 Film
01 (1st min.) Film 02 Film 03 Film 04 repeats . . . 501 Film 05
(1st min.) Film 06 Film 07 Film 08 repeats . . . 502 Film 09 (1st
min.) Film 10 Film 11 Film 12 repeats . . . 503 Film 13 (1st min.)
Film 14 Film 15 Film 16 repeats . . . 504 Film 17 (1st min.) Film
18 Film 19 Film 20 repeats . . . 505 Film 21 (1st min.) Film 22
Film 23 Film 24 repeats . . .
[0065] As will be apparent from Table 5, the invention permits at
least six different films per minute to be transmitted for receipt
by the STB receiver/recorder, with a one minute or less film start
delay. For example, the present invention's system and method
permits a 30 mbps signal composed of six times the bandwithd of the
original signal to guarantee a start time for each of 24 movies
with no more than a four minute delay. Thus, the invention permits
"n" number of multimedia content starts, per digital transmission
signal, wherein
1<n.ltoreq.M (1)
[0066] and further wherein M is the maximum number of channels per
signal.
[0067] In yet another embodiment, the scheduling of the data chunks
can be made dynamic, wherein the server-side computer determines a
schedule that best fits the start times of all people on the system
currently viewing that movie. In this way, the beginning packets of
the movie will only be sent when someone new begins viewing the
content, but will quickly "catch up" with the rest of the chunks
being transmitted. Thus, bandwidth requirements are further
reduced.
[0068] Another embodiment of the invention allows the bandwidth
requirements and startup times to be adjusted up and down as
required for an application. For example, to reduce the average
startup time to less than a minute simply requires reducing the
size of data chunks while using the same basic scheduling approach
already described, and does not significant increase the bandwidth
needed to send the IMS. To further reduce load on the server, the
smaller data chunk size need only be used for the first few minutes
of data, and moreover, the size of the data chunk could be adjusted
up or down as needed so long as the transmission schedule is always
observed. To decrease bandwidth requirements, a predetermined
minimal interval of time may be imposed between transmission of the
data chunks, which will reduce bandwidth requirements but increase
the average time a receiver must wait before it can start
displaying the content. For example, if a minimum of two minutes is
imposed, the first chunk of data which would normally be
transmitted once per minute would be sent once every two minutes
instead, reducing bandwidth but increasing the wait time for
starting to two minutes.
[0069] In yet another embodiment, a limited two-way connection
between the user/subscribers and the server may be provided which
facilitates scheduling and transmitting of the interleaved
multimedia stream. The user/subscriber's receiver or STB is capable
of sending a data signal to the server when the viewing of a
particular multimedia stream begins, which the server then uses to
dynamically change the transmission schedule, minimizing the
bandwidth required even further. According to this embodiment, the
server is able to determine when all receivers or STBs are "tuned"
into a particular IMS and whether they have received a particular
chunk of digital content. If all connected receivers are determined
to have received the particular chunk, the server then removes that
chunk from the transmission schedule. When a new request for the
content was received, the removed chunks are then placed back into
the schedule. How much of a bandwidth improvement this technique
would provide is difficult to estimate because it depends on how
frequently a new user requests a particular piece of content to
begin playing. In the case of a new request arriving every one
minute, the scheduling would not change from that shown in Table 2,
however if the average user requests are spread by as little as two
or three minutes the bandwidth requirements will drop noticeably,
and for films that are not requested frequently, this technique
could reduce bandwidth requirements dramatically.
[0070] As has been described herein, the present invention vastly
improves the bandwidth efficiency usage for large catalog content
VOD systems. The present invention's scheduling system and method
permit the allocation of channels which begin sending multimedia
content whenever a user/subscriber requests the selected multimedia
content. As different users/subscribers request the same movie, the
invention permits their addition to the transmission/viewing
schedule on a just in time basis. Since data chunks containing the
beginning segments are continually are sent along with the content
being transmitted and received by the STB of a first
user/subscriber, the invention reduces the costs of adding
additional users/subscribers to the interleaved multimedia stream
already in the process of being transmitted, as opposed to
conventional VOD systems where a unique multimedia stream of video
data is sent to each user/subscriber's STB. With the present
invention, no individual multimedia content product, e.g., a film,
consumes more than the maximum bandwidth per signal, e.g., about 30
mb of bandwidth, from the main video server or cable system
regardless of how many users/subscribers have requested and are
having such content transmitted to their STBs.
[0071] According to the present invention, if each short chunk of
digital content is transmitted according to the disclosed
transmission schedule, anyone may start receiving the interleaved
media stream at any time and begin watching the film from the
beginning within one minute. Any number of people may be receiving
the stream simultaneously and be a different times in the film with
no change in the streaming schedule. Because the transmission
schedule for each chunk of data can be easily predetermined and
never changes, very little computing power is required to schedule
the transmission of the data chunks that make up the IMS. This
allows a very inexpensive server computer to generate IMSs for many
different movies that can be tuned into by an unlimited number of
viewers. The hardware requirements for the receiver are similarly
undemanding and are easily within the capability of any digital
cable or satellite set-top-box equipped with a hard disk or other
form of storage device.
[0072] Although discussed primarily in terms of delivering video
data to users/subscribers, proposed VOD systems will generate data
streams which can also include audio, text, graphics and other data
types. All references to video data in the specification and claims
are intended to include data that comprises either entirely one of
these enumerated data types or some mixture of them. Further,
nothing herein should be taken to limit the present invention to
the storage and transmission of the specifically enumerated data
types only.
[0073] It shall be understood that various modifications will be
apparent and can be readily made by persons skilled in the art
without departing from the scope and spirit of the present
invention. Accordingly, the following claims shall not be limited
by the descriptions or illustrations set forth herein, but shall be
construed to cover with reasonable breadth all features which may
be envisioned as equivalents by those skilled in the art.
* * * * *